error(1)error(1)NAME
error - Analyzes and disperses compiler error messages
SYNOPSIS
error [-n] [-q] [-s] [-v] [-t suffix_list] [-I ignore_file] [file]
The error program analyzes and optionally disperses the diagnostic
error messages produced by a number of compilers and language proces‐
sors to the source file and line where the errors occurred.
OPTIONS
Takes the names of functions to ignore from ignore_file. If the -I
option is not specified, the function names are taken from a file named
in the user's home directory. If this file does not exist, no error
messages are nullified. Function names must be listed one per line in
ignore_file or in the file. Does not touch any files; all error mes‐
sages are sent to the standard output. Queries the user whether or not
to touch the file. You must enter y or n, or the locale's equivalent of
an affirmative or negative response, before continuing. If you do not
specify the -q option, all referenced files (except those referring to
discarded error messages) are touched by default. Prints out statis‐
tics regarding the error categorization. Does not touch files whose
suffixes do not appear suffix_list. The suffix list is dot-separated,
and * wildcards may be used. For example, the suffix list allows error
to touch files ending with and Overlays and sets up the visual editor
vi to edit all files touched, and positions the editor at the first
error in the first touched file. If vi cannot be found, try ex or ed
from standard places.
DESCRIPTION
Using the error program can replace the painful, traditional methods of
scribbling abbreviations of errors on paper, and permits error messages
and source code to be viewed simultaneously without machinations of
multiple windows in a screen editor.
The error program looks at the error messages, either from the speci‐
fied file file or from the standard input, and performs the following
operations: Attempts to determine which language processor produced
each error message. Determines the source file and line number to
which the error message refers. Determines if the error message is to
be ignored or not. Inserts the (possibly slightly modified) error mes‐
sage into the source file as a comment on the line preceding to which
the line the error message refers. Sends error messages that cannot be
categorized by language processor or content to the standard output;
does not insert these error messages into any file.
The error program touches source files only after all input has been
read.
The error program is intended to be run with its standard input con‐
nected via a pipe to the error message source. Some language proces‐
sors put error messages on their standard error file; others put their
messages on the standard output. Hence, both error sources should be
piped together into error. For example, when using the csh syntax, the
following command line analyzes all the error messages produced by
whatever programs make runs when making lint: make -s lint | error -q
-v
The error program knows about the error messages produced by the fol‐
lowing programs: as cc ccom cpp f77 ld lint make pc pi
The error program knows a standard format for error messages produced
by the language processors, so is sensitive to changes in these for‐
mats. For all languages except Pascal, error messages are restricted to
be on one line. Some error messages refer to more than one line in
more than one file; error duplicates the error message and inserts it
at all of the places referenced.
The error program does one of six things with error messages: Some lan‐
guage processors produce short errors describing which file it is pro‐
cessing. The error program uses these to determine the file name for
languages that do not include the file name in each error message.
These synchronization messages are consumed entirely by error. Error
messages from lint that refer to one of the two lint libraries,
/usr/libdata/lint/llib-lc and /usr/libdata/lint/llib-port are dis‐
carded, to prevent accidentally touching these libraries. Again, these
error messages are consumed entirely by error. Error messages from
lint can be nullified if they refer to a specific function, which is
known to generate diagnostics which are not interesting. Nullified
error messages are not inserted into the source file, but are written
to the standard output. The names of lint functions to ignore are
taken from either the file named in the user's home directory, or from
the file named by the -I option. If the file does not exist, no error
messages are nullified. If the file does exist, there must be one func‐
tion name per line. Error messages that cannot be “intuited” are
grouped together, and written to the standard output before any files
are touched. These messages are not inserted into any source file.
Error message that refer to a specific file, but to no specific line,
are written to the standard output when that file is touched. Error
messages that can be “intuited” are candidates for insertion into the
file to which they refer.
Only true error messages are candidates for inserting into the file to
which they refer. Other error messages are consumed entirely by error
or are written to the standard output. The error program inserts the
error messages into the source file on the line preceding the line the
language processor found in error. Each error message is turned into a
one-line comment for the language, and is internally flagged with the
string ### at the beginning of the error, and %%% at the end of the
error. This makes pattern searching for errors easier with an editor,
and allows the messages to be easily removed. In addition, each error
message contains the source line number for the line to which the mes‐
sage refers. A reasonably formatted source program can be recompiled
with the error messages still in it, without having the error messages
themselves cause future errors. For poorly formatted source programs in
free format languages, such as C or Pascal, it is possible to insert a
comment into another comment, which can wreak havoc with a future com‐
pilation. To avoid this, programs with comments and source on the same
line should be formatted so that language statements appear before com‐
ments.
The error program catches interrupt and terminate signals, and if in
the insertion phase, will orderly terminate what it is doing.
NOTES
Opens the teletype directly to do user querying. Source files with
links make a new copy of the file with only one link to it. Changing a
language processor's format of error messages may cause error to not
understand the error message. The error program, since it is purely
mechanical, does not filter out subsequent errors caused by “floodgat‐
ing” initiated by one syntactically trivial error. Humans are still
much better at discarding these related errors. Pascal error messages
belong after the lines affected (error puts them before). The align‐
ment of the \\ marking the point of error is also disturbed by error.
error was designed for work on CRTs at reasonably high speed. It is
less pleasant on slow speed terminals, and has never been used on hard‐
copy terminals.
FILES
Function names to ignore for lint error messages. User's teletype.
error(1)